1. Field of the Invention
This invention relates to a process for converting a halogenated organic material to an environmentally benign material, and more particularly for a process for converting a halogenated organic material into an easily disposed halide salt.
2. The Prior Art
Halogenated organic materials including halogenated organic solvents, such as polychlorinated biphenyl and halogenated organic solvents having heavy metals and other environmentally sensitive solutes dissolved therein, are harmful to the environment if disposed of improperly. In recent years the disposal of these materials has come under strict regulation, such disposal in many cases is almost impossible and what disposal methods are available are relatively expensive.
A conventional method of disposal involves the high temperature incineration of the halogenated organic materials and other chemical wastes followed with an expensive scrubbing of the effluent gas. Another method involves the incineration in areas where the combustion products and emissions from the incinerator are relatively safety dispersed. Several such methods are disclosed in U.S. Pat. Nos. 4,301,137; 3,888,193; 3,305,309; and 3,140,155. In U.S. Pat. No. 4,301,137, the gas stream obtained from the pyrolysis of a solid organic waste containing halogen is contacted with a solid metal halide acceptor (such as calcium carbonate) to form the corresponding metal halide which can then be discarded or regenerated. In U.S. Pat. No. 3,888,193, the organic wastes are heated in a fluidized medium of cement clinker granules which clinker granules fix acid gases, whereby the acid gases may be removed from the waste gas. U.S. Pat. No. 3,305,309 discloses a method for converting halogenated organic materials into carbon dioxide and hydrogen halide. U.S. Pat. No. 3,140,155 sets forth an apparatus for the conversion of halogenated organic compounds into gaseous products including carbon dioxide and hydrogen halide.
Ocean-going vessels are known which have been modified to carry cargoes of hazardous chemical waste out to designated areas of the ocean where the cargoes are incinerated at high temperatures and the gaseous products are dispersed over the vast ocean areas where they are considered to be less harmful.
The incineration of the halogenated organic materials is generally costly because the hydrogen halide or halogen gas produced by such processes must be scrubbed from the effluent gas. Such treatment requires new capital intensive equipment and generally requires a high consumption of costly materials. Further, unless the combustion is carefullly controlled small amounts of free halogen may be produced and vented to the atmosphere. The combustion also can be incomplete, allowing some hazardous materials to escape with the effluent gas into the atmosphere.
Co-assigned U.S. Pat. Nos. 3,687,646; and 3,671,209 disclose methods for the incineration and disposal of sewage and garbage, respectively. Even though these systems may be able to handle very small quantities of halogenated organic materials that may be incidently found in garbage and sludge, such methods cannot efficiently dispose of relatively large quantities of halogenated organic materials.